triiodothyronine--reverse and Liver-Diseases

Topics: Humans; Liver Diseases; Thyroid Hormones; Thyrotropin; Thyroxine; Thyroxine-Binding Proteins; Triiodothyronine; Triiodothyronine, Reverse

Topics: Female; Humans; Kidney Diseases; Labor, Obstetric; Liver Diseases; Pregnancy; Thyroid Diseases; Triiodothyronine, Reverse

Possible arterio-venous gradients of T4, T3, rT3 and 3,3'-diiodothyronine (3,3'-T2) across the liver and the kidneys were measured in 9 patients with varying degrees of liver failure undergoing diagnostic catheterization. Plasma iodothyronine levels were measured in peripheral, hepatic and renal veins before and at 10-min intervals until 60 min after iv injection of 400 micrograms of TRH. In 2 patients estimated hepatic plasma flow and effective renal plasma flow were determined as well. In these 2 patients, no significant differences between iodothyronine levels in arterial and peripheral venous plasma were found. T4 and T3 levels were not significantly different between peripheral, renal and hepatic veins. Hepatic vein rT3 and 3,3'-T2 concentrations were 10.7 +/- 8.3% (mean +/- SD, P less than 0.005) and 36 +/- 18% (P less than 0.001) lower than those in the peripheral vein (N = 9). Renal vein rT3 was just (6.2 +/- 7.5%, P less than 0.05) lower than rT3 in peripheral vein, whereas 3,3'-T2 was not different between the two veins. Estimates of hepatic and renal plasma flow were in agreement with values from the literature. On the basis of these data approximate hepatic clearance rates of 110 and 380 1/day for rT3 and 3,3'-T2 and a renal clearance rate of about 35 1/day for rT3 were calculated. Sixty min after TRH, plasma T3 was increased to 147 +/- 56% (P less than 0.05) and 3,3'-T2 in peripheral plasma was increased to 142 +/- 36% (P less than 0.025), whereas plasma T4 and rT3 did not change.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Aged; Chronic Disease; Diiodothyronines; Female; Humans; Kidney; Liver; Liver Diseases; Male; Middle Aged; Thyroid Hormones; Thyrotropin-Releasing Hormone; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse

Basal T4, T3, TSH, prolactin and growth hormone levels were determined in several groups: patients with postnecrotic cirrhosis with hepatocellular carcinoma (n = 14); patients with postnecrotic cirrhosis but without hepatocellular carcinoma (n = 26); cholangiolar carcinoma (n = 9); and normal controls age-matched to within 5 yr of the liver disease subjects studied. In addition, TRH stimulation (400 micrograms TRH) was performed; TSH, prolactin and growth hormone responses over a 180-min time interval were evaluated for each subject. The responses observed varied between liver disease groups. The presence or absence of hepatocellular carcinoma was found to determine, at least in part, the type of response observed. Similarly, the presence or absence of hepatic encephalopathy determined, and/or reflected, at least in part, the type of response observed. Finally, for purposes of continuity, basal and TRH-stimulated levels of TSH, prolactin, growth hormone, T4 and T3 are compared in 3 settings of cirrhosis: alcoholic, nonalcoholic postnecrotic cirrhosis, and postnecrotic cirrhosis with hepatocellular carcinoma.

Topics: Carcinoma, Hepatocellular; Growth Hormone; Hepatic Encephalopathy; Humans; Liver Diseases; Liver Neoplasms; Pituitary Hormones; Prolactin; Thyroid Hormones; Thyrotropin; Thyrotropin-Releasing Hormone; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse

Earlier demonstration of elevated blood thyroid hormones and transaminase activities during controlled chamber dives to 540 and 660 msw [at AMTE(PL), Gosport, England; 1980 and 1981] led to the suspicion that high compression may interfere with liver function. Further studies, here described, of blood thyroid hormone level changes during the course of subsequent dives indicate that thyroxine and reverse triiodothyronine elevations are to be expected during any period of sustained compression, to depths as shallow as 61 msw. Moreover, blood levels of thyroxine-binding globulin (TBG), measured in the 540 and 660 msw dives, were also shown to rise, probably accounting for the hormone changes. This elevation is not confined to TBG, being demonstrable in at least six other glycoproteins (sex hormone-binding globulin, transferrin, ceruloplasmin, haptoglobin, alpha 1 acid glycoprotein, and alpha 2 macroglobulin). Since all these proteins share identical or very similar metabolic fates within the liver, these findings lend further weight to our hyperbaric liver dysfunction theory. How such disturbances may come about is discussed, together with its possible implications apropos high pressure nervous syndrome and divers' well-being and capabilities while at depth.

Topics: Diving; Enzymes; Glycoproteins; Humans; Liver Diseases; Male; Serum Albumin; Thyroid Hormones; Thyrotropin; Thyroxine; Thyroxine-Binding Proteins; Triiodothyronine; Triiodothyronine, Reverse

Topics: Adult; Aged; Female; Humans; Liver Diseases; Male; Microsomes, Liver; Middle Aged; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse

ātients with end-stage chronic renal failure (CRF) and those receiving dialysis therapy have normal or decreased serum total T4 (TT4), reduced serum total T3 (TT3), and normal total reverse T3 (TrT3) levels. Those with nonrenal nonthyroidal illnesses or malnutrition have low TT4 and TT3 but elevated TrT3 values. To evaluate the mechanism(s) for the normal TrT3 levels in CRF, we performed intravenous bolus kinetic studies of rT3 and T4 in patients with CRF, in those treated with chronic hemodialysis, in patients with nonrenal nonthyroidal illnesses, and in normal subjects. The CRF patients were selected to have good nutritional status as indicated by normal serum transferrin, relative body weight, and body mass index values. The CRF patients had normal TrT3, TT4, and free T4 values, increased free fraction of rT3, free rT3, and thyroxine-binding globulin levels, and decreased TT3 concentrations. Noncompartmental analysis of the rT3 kinetics indicated normal production rate, reduced cellular clearance rate, and increased pool size and residence time values in both the CRF and nonrenal patients. In CRF, the serum clearance rate was normal, but the fractional rate of exit, permeability, extravascular binding, and the apparent volume of distribution were increased. In contrast, the nonrenal patients had reduced serum clearance rate, permeability, and extravascular binding, whereas the fractional rate of exit and apparent volume of distribution were not significantly altered. The T4 kinetics in CRF paralleled those of the nonrenal patients, with a reduced fractional rate of exit and permeability in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Aged; Body Weight; Chronic Disease; Female; Humans; Infections; Kidney Failure, Chronic; Kinetics; Liver Diseases; Male; Middle Aged; Nutritional Physiological Phenomena; Renal Dialysis; Respiratory Insufficiency; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse; Uremia

We studied various tests of thyroid function in sick patients with nonthyroidal illness (NTI) in order to determine the utility of each test for differentiating these patience from a group with hypothyroidism. We evaluated each test in 22 healthy volunteers who served as controls, 20 patients with hypothyroidism, 14 patients admitted to medical intensive care unit whose serum T4 was less than 5 micrograms/dl, 13 patients with chronic liver disease, 32 patients on chronic hemodialysis for renal failure, 13 ambulatory oncology patients receiving chemotherapy, 16 pregnant women, 7 women on estrogens, and 20 hyperthyroid patients. On all samples, we measured serum T4, the free T4 index by several methods, free T4 by equilibrium dialysis, free T4 calculated from thyronine-binding globulin (TBG) RIA, free T4 by three commercial kits (Gammacoat, Immophase, and Liquisol), T3, rT3, and TSH (by 3 different RIAs). Although all of the methods used for measuring free T4 (including free T4 index, free T4 by dialysis, free T4 assessed by TBG, and free T4 assessed by the 3 commercial kits) were excellent for the diagnosis of hypothyroidism, hyperthyroidism, and euthyroidism in the presence of high TBG, none of these methods showed that free T4 was consistently normal in patients with NTI; with each method, a number of NTI patients had subnormal values. In the NTI groups, free T4 measured by dialysis and the free T4 index generally correlated significantly with the commercial free T4 methods. Serum rT3 was elevated or normal in NTI patients and low in hypothyroid subjects. Serum TSH provided the most reliable differentiation between patients with primary hypothyroidism and those with NTI and low serum T4 levels.

Topics: Alpha-Globulins; Chronic Disease; Female; Humans; Hyperthyroidism; Hypothyroidism; Kidney Failure, Chronic; Liver Diseases; Neoplasms; Pregnancy; Radioimmunoassay; Reagent Kits, Diagnostic; Renal Dialysis; Thyroid Function Tests; Thyrotropin; Thyroxine; Thyroxine-Binding Proteins; Triiodothyronine; Triiodothyronine, Reverse

The low thyroxine (T(4)) state of acute critical nonthyroidal illnesses is characterized by marked decreases in serum total T(4) and triiodothyronine (T(3)) with elevated reverse T(3) (rT(3)) values. To better define the mechanisms responsible for these alterations, serum kinetic disappearance studies of labeled T(4), T(3), or rT(3) were determined in 16 patients with the low T(4) state and compared with 27 euthyroid controls and a single subject with near absence of thyroxine-binding globulin. Marked increases in the serum free fractions of T(4) (0.070+/-0.007%, normal [nl] 0.0315+/-0.0014, P < 0.001), T(3) (0.696+/-0.065%, nl 0.310+/-0.034, P < 0.001), and rT(3) (0.404+/-0.051%, nl 0.133+/-0.007, P < 0.001) by equilibrium dialysis were observed indicating impaired serum binding. Noncompartmental analysis of the kinetic data revealed an increased metabolic clearance rate (MCR) of T(4) (1.69+/-0.22 liter/d per m(2), nl 0.73+/-0.05, P < 0.001) and fractional catabolic rate (FCR) (32.8+/-2.6%, nl 12.0+/-0.8, P < 0.001), analogous to the euthyroid subject with low thyroxine-binding globulin. However, the reduced rate of T(4) exit from the serum (Kii) (15.2+/-4.6 d(-1), nl 28.4+/-3.9, P < 0.001) indicated an impairment of extravascular T(4) binding that exceeded the serum binding defect. This defect did not apparently reduce the availability of T(4) to sites of disposal as reflected by the increased fractional disposal rate of T(4) (0.101+/-0.018 d(-1), nl 0.021+/-0.003, P < 0.001). The decreased serum T(3) binding was associated with the expected increases in MCR (18.80+/-2.22 liter/d per m(2), nl 13.74+/-1.30, P < 0.05) and total volume of distribution (26.55+/-4.80 liter/m(2), nl 13.10+/-2.54, P < 0.01). However, the unaltered Kii suggested an extravascular binding impairment comparable to that found in serum. The decreased T(3) production rate (6.34+/-0.53 mug/d per m(2), nl 23.47+/-2.12, P < 0.005) appeared to result from reduced peripheral T(4) to T(3) conversion because of decreased 5'-deiodination rather than from a decreased T(4) availability. This view was supported by the normality of the rT(3) production rate. The normal Kii values for rT(3) indicated a comparable defect in serum and extravascular rT(3) binding. The reduced MCR (25.05+/-6.03 liter/d per m(2), nl 59.96+/-8.56, P < 0.005) and FCR (191.0+/-41.19%, nl 628.0+/-199.0, P < 0.02) for rT(3) are compatible with an impairment of the rT(3) deiodination rate. These alterations in thyroid hormo

Topics: Acute Disease; Adult; Aged; Binding Sites; Female; Humans; Infections; Kinetics; Liver Diseases; Male; Metabolic Clearance Rate; Middle Aged; Respiratory Insufficiency; Thyroxine; Thyroxine-Binding Proteins; Triiodothyronine; Triiodothyronine, Reverse

There is a recent hypothesis that thyroxine (T4), secreted by the thyroid gland under physiological conditions, is mono-deiodinated in extrathyroidal sites to form the more active 3, 3', 5-tri-iodothyronine (T3) before exerting biological activity at target tissue level. Futhermore, circumstantial evidence suggests that the liver is an important site for the extra-thyroidal conversion of T4 to T3. Thyoid hormone pathophysiology in liver disease is therefore of interest. Patients with hepatic cirrhosis have normal or raised plasma T4 concentration and markedly reduced plasma T3 concentration. Free hormone measurement reflect this pattern and three is kinetic and other evidence to support the concept that extra-thyroidal conversion of T4 to T3 is reduced in patients with liver dysfunction. Comparable finding have however been reported in patients with other non-hepatic chronic systemic diseases but, unlike in hepatic cirrhosis, serum thyrotropin (TSH) is not increased. Increased serum TSH is found in hepatic cirrhois and is often accompanied by an abnormal TSH response to thyrotropin-releasing hormone (TRH) suggesting, in addition, disordered hypothalamic-pituitary control of thyroid function in these patients. Thyroid physiology is clearly markedly disturbed in hepatic cirrhosis but no single hypothesis adequately accounts for all the observed abnormalities. The recent finding of increased plasma 3, 3', 5-tri-iodothyronine (reverse t3; rT3) concentration in hepatic cirrhosis may ulimately clarify our understanding.

Topics: Humans; Liver Diseases; Thyroid Gland; Thyrotropin-Releasing Hormone; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse

Levels of serum triiodothyronine (T3), reverse triiodothyronine (rT3), and thyroxine (T4) were determined in 29 patients with alcoholic cirrhosis, seven patients with acute hepatitis, and 14 control patients hospitalized for chronic disease. Serum T3 levels were decreased significantly and serum rT3 levels increased significantly in the patients with alcoholic cirrhosis. Serum T3 and T4 levels were lower and rT3 levels higher in the cirrhotic patients who died within three months of the study compared with those who survived. A combination of prothrombin time, aminopyrine breath test results, and rT3 and T3 determinations gave significant predictive information about survival in patients with cirrhosis. The data suggest that assay of serum thyroid hormone levels together with prothrombin time and the aminopyrine breath test may be helpful in assessing the course and prognosis of patients with liver disease.

Topics: Adult; Aged; Breath Tests; Hepatitis; Humans; Liver Cirrhosis, Alcoholic; Liver Diseases; Middle Aged; Prognosis; Prothrombin Time; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse